Procedure for dry cleaning

ABSTRACT

DRY CLEANING COMPOSITIONS CONTAINING HYDROPHILIC OPTICAL BRIGHTENER AND DETERGENT MATERIAL COMPATIBLE THEREWITH CAN BE USED IN CONVENTIONAL COIN-OPERATED, PROFESSIONAL AND, PREFERABLY, INDUSTRIAL DRY CLEANING SYSTEMS TO SIMULTANEOUSLY CLEAN AND BRIGHTEN TEXTILE STRUCTURES AND PARTICULARLY WHITE GARMENTS CONTAINING A SIGNIFICANT MANMADE FIBER CONTENT.

United States Patent 3,640,881 PROCEDURE FOR DRY CLEANING Francis SelimMoussalli, Charlotte, N.C., assignor to Celanese Corporation, New York,N.Y. No Drawing. Filed July 24, 1968, Ser. No. 747,074 Int. Cl. C09d9/04; (311d 7/52; C23g /02 U.S. Cl. 252171 11 Claims ABSTRACT OF THEDISCLOSURE Dry cleaning compositions containing hydrophilic opticalbrightener and detergent material compatible therewith can be'used inconventional coin-operated, profes sional and, preferably, industrialdry cleaning systems to simultaneously clean and brighten textilestructures and particularly white garments containing a significantmanmade fiber content.

BACKGROUND OF THE INVENTION This invention relates to the dry cleaningarts. More particularly, this invention relates to dry cleaning systemscontaining uniquely compatible cleansing agents and optical brightenersin which textiles, and particularly white fabrics, whether made ofnatural fibers, man-made fibers or blends thereof, can be quickly,conveniently and repeatedly thoroughly cleansed in conventional drycleaning equipment with excellent removal of lipophilic and hydrophilicas well as non-soluble soiling materials without causing the material tofade or discolor, yellow, degrade, pill or develop other highlyundesirable characteristics.

As used within this specification and the appended claims, dry cleaningrefers to numerous and varied cleansing processes normally considered tobe encompassed by the term as used by those skilled in the art and,generally, refers to the employment of fluid, and particularly liquid,hydrophobic, organic cleaning solvents in systems in which the textilearticles remain dry only in the sense that the solvent does notextensively penetrate individual fiber filaments causing them to becomewet or swollen as cotton becomes in aqueous media. Conventional drycleaning systems in wide use today generally employ either a halogenatedhydrocarbon solvent, such as carbon tetrachloride, trichloroethylenerand perchloroethylene, or a petroleum naphtha cut such as Stoddardssolvent as the predominant solvent-cleaner.

The dry cleaning solvents of choice are characterized by theirnon-flammability, short drying times, and excellent dispersion andsolvation properties for hydrophobic soiling substances. However, suchsolvents due to their organic nature are not capable of thoroughlycleaning textile materials exhibiting hydrophilic surfaces or heavilysoiled with water-soluble contaminants. Particularly critical problemshave developed with attempts to dry clean white or other light, e.g.,pastel colored, garment fabrics, and in particular, white fabrics havinga man-made fiber content, due to the natural tendency of white textilesto yellow during prolonged exposure to light and the inability ofconventional dry cleaning systems to arrest this progressive fading orcolor change during the dry cleaning process. Additionally,water-soluble stains and soils tend to become permanently embedded orset in fabrics during dry cleaning and subsequent pressing. Thus, inaddition to designing a dry cleaning system capable of removing bothwater and organic solvent-dispersible soils as well as non-solubleparticulates from the material, it is a necessary and essentialrequirement that the dry cleaning procedure retain, and, if required,restore the treated articles to a condition closely approximating thecharacteristics and appearance of the material when new. The above isespecially crucial for white light weight and heavy weight garmentscontaining synthetic fibers, whether intimately blended with naturalfibers or not, which are subjected to frequent soiling necessitatingcleaning following only one or two wearings, such as shirts, blouses,work pants, uniforms and the like. These fabrics exhibit color, luster,hand, wrinkle resistance, abrasion resistance, dimensional stability andother highly desirable properties which must be maintained throughoutnumerous cleaning cycles over the normal expected life of the garment.As examples of synthetic or man-made fibers used in wearing apparel andother textiles, there may be mentioned polyesters, acetates, bothsecondary and triacetate, polyamides, polyolefins and the like, whichmay be utilized in interwoven fabric constructions comprising percentsynthetic or may be present in blends of e.g. 35 to 65 percent cotton orthe like.

Therefore, it is an object of the present invention to provide drycleaning compositions and processes for thoroughly cleaning textiles ofall types of soiling substances without deleteriously affecting theirhighly desirable characteristics such as dimensional stability, abrasionresistance, hand, color and the like. It is still another object of thepresent invention to provide dry cleaning compositions and processes forcleaning highly soiled white garments, particularly white garmentscontaining fabrics formed from intimate synthetic fiber/natural fiberblends, which in addition to substantially completely removing all soilmaterial from the fabric, restore the fabric to its original white colorwithout adversely affecting other Wanted fabric properties. It isanother object of the present invention to provide dry cleaning systemscontaining uniquely compatible cleansing agents and optical brightenersdispersed throughout conventional dry cleaning solvents particularlysuitable for simultaneously cleaning and brightening highly soiled whitepolyester/cotton wearing apparel without lower abrasion resistance or inany other manner decreasing the normal life span of the garment. Otherobjects of the invention will appear obvious to those skilled in the artfrom the detailed description of the invention hereinafter.

THE INVENTION The present invention eliminates the problems existent inconventional dry cleaning processes preventing their employment in thedry cleaning of many types of textile materials such as white fabrics of100 percent natural and man-made fiber content and man-madefiber/natural fiber blends, by providing a dry cleaning solvent systemformulated with a water-dispersible, and preferably water soluble,optical brightener and a compatible detergent material contained withina conventional dry cleaning solvent admixed with a small quantity ofwater. Additionally, the present invention provides a process forformulating a dry cleaning system comprising a dry cleaning solventcontaining an intimate dispersion of water, detergent and opticalbrightener and a process for using the formulation so prepared forthoroughly cleaning and brightening white fabrics.

It is to be understood that the designations textile, fabric, and thelike are used herein throughout the specification and appended claimsinterchangeably and include within their scope every type of textilestructure regardless of precise technical classification as woven,knitted, non-woven, and the like.

In accordance with the present invention, dry cleaning systems forcleaning textiles while maintaining and improving their desirableproperties such as luster and finish are provided comprising aconventional dry clean: ing solvent such as perchloroethylene andStoddards solvent containing an ionic or nonionic cleansing agent, awater dispersible, hydrophilic optical brightening agent physically andchemically compatible with the detergent and a small quantity offinely-dispersed water. In a preferred embodiment of the invention, thecleaning agent is an amphoteric detergent and the optical brightener isa water soluble, anionic, stilbene brightener.

Another aspect of the invention is described to a method for preparingthe above-disclosed dry cleaning formulation which comprises injectingand thoroughly admixing an aqueous dispersion, preferably a solution ofan optical brightener, optionally containing an amphoteric detergent, ina dry cleaning solvent. In another aspect of the present invention,which may be considered as another preferred embodiment thereof, thereis disclosed a sequential multistep process for dry cleaning textilematerials, specifically white fabrics containing cotton fibers blendedwith a synthetic fiber such as a polyester, polyamide, acetate,polyolefin and the like, usable in conventional dry cleaning equipment.This process, which results in clean, bright articles, is described indetail hereinafter.

DETAILED DESCRIPTION OF THE INVENTION This invention is based in partupon the discovery that in conventional organic dry cleaning systems awaterdispersible optical brightener in the presence of a small volume ofwater can function as a brightness restorer preventing the textilestructures being dry cleaned from dullin-g, fading, yellowing oracquiring other undesirable characteristics. In addition, it has beenfound that the employment of a detergent material, especially those ofthe amphoteric type, enhances the brightening efiect produced by theoptical brightener. The brightener is dispersed, or preferably,dissolved in a predetermined quantity of water which is then added tothe dry cleaning solvent by means of conventional dry cleaning injectionequipment. To assure uniform dispersion and mixing of the aqueous phasethroughout the hydrophobic organic solvent, the water system is injectedinto the cleaning vessel containing the solvent over a period of two tothree minutes prior to or during rotation of the dry cleaning drum.

In the preferred embodiments of the invention, the detergent, which maybe a chemical entity or a mixture of two or more compositions exhibitingthe necessary polar nature and/ or ionic distribution for classificationas a detergent substance, may be admixed with the dry cleannig solventeither prior or subsequent to the injection of the water dispersion ofbrightener into the dry cleaning solvent. If sufficiently compatiblewith the optical brightener- Water system due to judicious selection ofingredients, the detergent may be admixed with the brightener prior toinjection of the aqueous system into the dry cleaning solvent.Preferably, the detergent is charged to the solvent through an injectorand thoroughly dispersed throughout the system prior to the addition ofthe optical brightener.

The terms water-dispersible optical brightener, nonionic detergen ionicdetergent, cationic detergent, anionic detergent and amphotericdetergent as used herein and in the appended claims refer tocompositions of matter, whether individual compounds or mixtures of twoor more compounds, which possess the desired chemical and physicalcharacteristics which enable them to function respectively as textileoptical brighteners orv detergents, as those terms are generally used inthe art, in the particular dry cleaning solvent system being used.

Accordingly, the term water-dispersible optical brightener includeswithin its scope any of a number of known water-dispersible compoundswhich improve color brightness, and particularly whiteness of textilematerials. Optical brighteners exhibit various degrees of solubility inwater depending upon the number and type of hydrophobic substituentgroups attached to the central organic moiety. In choosing an opticalbrightener the essential consideration is that the brightener willremain substantially in the water phase under the existing conditions ofusage. (Although it may, of course, be preferentially disposed about thewater-organic solvent interface.) Therefore, due to the various physicalchemical changes possible in commercial and particularly industrial drycleaning techniques, i.e. temperature, pressure, choice of organicsolvent, percentage water and the like, a rigid rule for selection ofbrightener component need not be stated. As examples of stilbene opticalbrighteners which should function satisfactorily under most of theenvironmental conditions found in industrial laundries, there may bementioned certain of the bis-triazinyl derivatives of4,4'-diaminostilbene- 2,2'-disulfonic acid prepared from one mole of thereaction product of two moles of cyanuric chloride and one mole of thedisodium salt of diaminostilbene disulfonic acid with two moles ofaniline. To enhance water solubility of the compound, the two remainingchlorine groups on the triazine rings are replaced by amine groupscontaining hydrophilic substituents such as N-methylethanolamine anddiethanolamine. Other examples of stilbene optical brighteners having agood degree of water solubility are naphthotriazolyl stilbene sulfonicacid and other fully sulfonated, amine substituted cyanuricchloride-disodium diaminostilbene disulfonate reaction products.

Optical brighteners function by absorbing invisible ultravioletradiation and emitting the same in the visible spectrum, preferably asblue-White light. Thus, the optical brightening agent actually generateswhite visible light which is seen as part of the total light reflectanceof the material containing the brightener. When used with fabrics havinga natural tendency to yellow, the additional reflected light,particularly if blue-white, mask any yel low discoloration, deceleratesthe yellowing process and gives a pronounced whitening effect to thefabric. At the present time, no one has adequately explained in whatmanner optical brighteners associate with textile materials. It isbelieved that the factors involved are those probably accounting for dyeuptake, namely, a combination of hydrogen bonding, Van der Waals forcesand aggregation. While all three factors are probably involved withhydrophilic substrates, the main attractive force with synthetic fiberssuch as polyester, polyamide, and polyolefin is probably that of Van derWaals forces.

In a like manner, the dry cleaning detergent materials may be selectedfrom many of the vast number of cleaning agents currently available tothe dry cleaning industry. As examples of these, there may be mentionedamine sulfonates, such as isopropylamine dodecyl benzene sulfonate,sorbitan fatty acid esters, petroleum sulfonates, phosphate esters suchas sodium dodecyl phosphate, ethoxylated alkyl phenols such asethoxylated nonyl phenol and nonylphenoxy-poly(ethyleneoxy) ethanolsuccinates such as sodium di(ethyl hexyl) sulfosuccinate andcombinations thereof. The most important property which the detergent,whether cationic, anionic, or nonionic, must possess is that ofcompatibility with the optical br ghtener. For instance, with theemployment of an anionic optical brightener, such as a stilbenebrightening agent, the detergent material should be either nonionic oranionic to avoid possible chemical inter-action, precipitation, orneutralization of ingredients.

Similarly the term amphoteric detergent encompasses cleansing agentsbroadly regardless of technical classification as a naturally-occurringdetergent, synthetically produced material, saponified material and thelike. The critical determination to be made in the selection of thispreferred type of cleansing agent is to be certain that it exhibitsamphoteric properties, that is, the detergent material has both acid andbasic properties, or the capacity to simultaneously react as an acidorbase. A secondary consideration, of course, is that the selecteddetergent must be compatible with the solvent system containing minutesuspended droplets of Water. One class of amphoteric compounds, theampholytic surface active detergents, are particularly useful in thepresent invention.

Considering the selection of an amphoteric detergent material in greaterdetail, a cursory examination of a struc- .5 g tural formulawithres'pect to apparent potential reactivity for both acids and basesis oftenlmisleading and inconclusive as to the possible amphotericproperties of the compound in question. A perfunctory determinationbased upon chemical formulae can be especially misleading in determiningthe possible amphoteric nature of surface activematerials due to theirgeneral complex chemical structure; the-presence of a number of groupswithin the complex molecule possessing various degrees of basicity andacidity as measured by' proton donation or acceptance, Lewis acid andbase determination and the like factors; and thepresence of positivelyand'negativelycharged groups. A fairly reliable test to determineamphoterism is to measure the acid and base dissociation constants ofthe compound in question. In general, if the values are small and aboutthe same, the compound is likely to possess true amphoterism.

As examples of amphoteric'detergents, there may be mentioned the alkylamino-carboxylic acids of the formula RR'NR"COOH wherein R is a highalkyl group of over 8 carbon atoms, R is lower alkyl or substitutedlower alkyl and R" is an alkylene radical of up to about 4 carbon atoms.Many of the amino carboxylic amphoteric detergents will contain two ormore substituted amino groups such as compounds of the general formula 1wherein R is long chain alkyl ranging up to 12 or more carbon atoms andR, R and R are selected from H or short chain alkyl. Other examples ofamino carboxylic acid amphoteric surface active agents, all of which arewell known in the art, are the halogenated reaction products of aminocarboxylic acids with the condensation products of 3 to 30 molesethyleneoxide with alcohols, including phenols containing about 6 carbon atoms,and the condensation products of naturally-occurring fatty acids such ascoconut oil fatty acids with hydroxy amines such as diethanolamine anddiis'opropanolamine.

Another large group of amphoteric detergents are sulfonic acids of thegeneral formula wherein R is a long chain alkyl group of over carbonatoms and R and R are low molecular weight alkyl and cycloalkyl groups.

Other amphoteric detergents are the condensation products of glycidylethers and di-lower alkyl amino sulfonates.

As additional examples of the above amphoteric compounds, there may bementioned:

Na-( l-dodecyloxy-2-hydroxypropyl) N-rnethylaminoethanesulfonate,N-dodecyl-N-methyltaurine, N-dodecyl-N-ethyltaurine, 4-octodecyl-4-aminobutyric acid, 4-pentodecyl-4-amino butyric acid With the employment ofthe compositions and process of the present invention, textiles,particularly if containing a synthetic fiber such as polyester, may berepeatedly dry cleaned without concern as to modification of the fabriccolor, hand, finish, texture, overall appearance and other properties.With the practice of the present invention, polyester-containinggarments heavily soiled by water and/or oil dispersible agents can bethoroughly cleansed in an inexpensive manner with conventionalcoin-operated, professional and industrial dry cleaning equipmentwithout danger of fading and yellowing. Garments and other textilearticles of all colors remain at least as bright after cleaning as theywere before undergoing the cleaning process. Although the invention isdescribed with reference to one of its preferred embodiments in the drycleaning of polyester-cotton garments, it

is to -be understood, of course, that the system may be employed withany type of article not deleteriously affected by the dry cleaningprocess.

Without wishing to be bound by one particular theory or explanation forthe unexpected results flowing from the use of the invention, it isbelieved that the invention is dependent upon the employment inconventional dry cleaning systems of a particular combination ofwaterdetergent-brightener as disclosed hereinbefore. The water phasecontaining the hydrophilic optical brightener would normally be expectedto be uniformly dispersed in finely suspended droplets throughout theorganic dry cleaning solvent phase. However, with the addition of thedetergent, and particularly an amphoteric detergent, to the dry cleaningsystem, it'is hypothesized that the detergent, due to its polar nature,ionic distribution, combination of positive and negative charges and/orother intrinsic factors concentrates near the fabric surfaces dnawingthe water droplets containing the brightening agent thereto.Consequently the detergent and optical brightener remain highlyconcentrated in the immediate vicinity of the soiled fabric surfacesinstead of being uniformly dispersed throughout the dry cleaningsolvent. For this reason, other water-attnacting material such asinorganic salts should not ordinarily be added to the system. However,various compatible adjunctive agents such as additional cleansingagents, wetting agents, anti-foaming agents, buffering agents, viscosityregulators and the like normally soluble or dispersible in the organicor aqueous phase may be readily used during the cleaning operation.

As disclosed hereinbefore, an important feature of the present inventionresides in the discovery that water dispersible optical brighteners canbe used aduantageously in hydrophobic dry cleaning systems. To this end,it is critical that a small quantity of water, at times less than 1volume percent based on the volume of dry cleaning solvent, be presentin the cleaning system. 'Usually the quantity of water containing theoptical brightener which is injected into the solventwill suifice toform a relatively stable dispersion of water droplets which will supplythe necessary amount of water. If for some reason a substantialproportion of the water should be removed from the solvent system duringthe cleaning cycle, such as from absorption by dry, hydrophilicmaterials being cleaned, additional water may be injected into thesystem.

Generally, the ingredients used in the present invention may be employedin a broad range of about 1,000 p.p.m. to 0.01 p.p.m. (w./v.) for theoptical brightener, about 5 to 0.04 percent (W./v.) for the detergentand about 7.0 to 0.04 percent (v./v.) for the water, all based upon thedry cleaning solvent, and prefenably the formulation will consist of 10to 0.1 p.p.m. (w./v.) optical brightener, 2 to 0.3 percent (w./v.)detergent and 4.0 to 0.5 percent water, with the balance being solvent.Most preferably, the dry cleaning system will contain 2 p.p.m. (W./v.)brightening agent, 0.375 percent (w./v.) detergent and 0.75 percent(v.'/v.) water based on the organic solvent.

Of course, the above general percentages of ingredients in theformulation can vary widely depending upon the relative strengths of theparticular optical brightener and detergent employed and type ofmaterial being treated. For instance, many of the newer entirelysynthetic detergent materials are operable at low concentrations whileamphoteric detergents prepared from, for example, naturally occurringfatty acids will often be required in higher concentrations approachingpercent (w./v.) and above based on the dry cleaning solvent.

At times, particularly when the optical brightener is astilbene-containing compound and the brightener formulation is to beprepared in bulk quantities for use over a period of 3 or 4 days orlonger, the large molecules of the optical brightener may begin toprecipitate out of solution and collect at the bottom of the storagevessel as a fine powder. Although redispersion and agitation ofbrightener in the water prior to usage would appear toredissolve the 7compound, it may be desired to incorporate an inert, adjunctive solventin the brightener formulation to assure stable solvation over longperiods of time. The particular solvent system employed will not becritical as long as the formulation will provide the necessaryquantities of brightener and water when added to the dry cleaning systemand the additional solvent remains inert throughout the cleaningprocess. The solvent system must retain its hydrophili-c character andwill usually contain a substan- Although this exampleillustrates onepreferred embodiment of the invention it will be obvious to those ofordinary skill'in the art to modify the overall process in various wayssuch as by manipulating' the' order of process steps; addingconventional dispersion, anti-foam and the like agents to the system;substituting other compatible non-ionic, anionic and cationic detergentsfor the Emerbrite 75.15 and Emerbrite 3723; and substituting otheroptical brighteners ,for the one specified in the example.

y 5 percent q y of water- As'examples Additionally, one cleaningcyclemay be preferable in of such ad unctive solvents, there may be mentionedcelsome instances i g" upon the type and o f losolve, methylceuosolveand methylethylkeiomi' textile being cleaned 'de'gr'ee of soilingpresent andthe The following examples are Presented lnustrate like, allof which is within the skill of those working in min Preferred F PW ofthe invent1n and not the art. Usually, the percentage ofwater used inthe dry to be consumed as llmltmg P Scope of the mventlol} as cleaningsystem is sufficient to raise the solvent pressure defined by aPPerfdedclalms- All Parts are by Welght in the filter above a reasonablysafelevel in conventional unless Otherwlse mdlcatedperchloroethyleneindustrial dry cleaning systems if the EXAMPLEI solvent containing .theWater is. subjected to filtration. Therefore, in the preferred processthe solvent from the (a) first cleaning cycle is'distilled and notfiltered. Of course,

This example illustrates one of the preferred embodiwith the use ofimprovedfiltration equipment, one cleanments of the invention for drycleaning heavily soiled ining cycle could suflice. dustrial garments bymeans of a multi-step dry cleaning process applicable for use inconventional industrial dry EXAMPLE cleaning equipment. (a)

Initially, a stable optical brightener solution is prepared Example I isrepeated fi '8 the fbllowin'g dry d e ani n by dissolving two partsstilbene optical brightener Tinopal t Y g 4BM/ 154 available from GeigyChemical Corporation in iggg g m the first cleanmg cycle with equallygood 80 parts boiling water, allowing the solution to cool to Y i p vabout 80 degrees centigradeand then adding 18 partsNonylphenoxy-poly(ethyleneoxy) ethanol noneionic de- Cellosolve withagitation to produce a stable solution of 2 tergent0.5 percent (w./v.)percent optical brightener which may be stored in a light Tinopal BHSwater soluble optical brightener available impervious container untilneeded. from Geigy Chemical Corporation- 6 p.p.r n.

Thirty pounds of white work uniforms of 65 percent Water-2 percent(v./v.) polyester/ percent cotton fiber content heavily soiled 35Perchloroethylene-- gallons with dirt, grease, oil and perspiration areplaced in a b conventional rotatable dry cleaning basket of standardconstruction containing 40 gallons of perchloroethylene. Part (a) ofthis example is repeated with Tinopal 4 Utilizing conventional injectiondry cleaning equipment, 40 BM/154 optical brightener with equally goodresults.

24 ounces of the 2 percent optical brightener solution and 12 ounces ofEmerbrite 7515 amphoteric detergent avail- EXAMPLE HI able from EmeryIndustries, Inc., are charged to the clean- This example illustrates thesuperior results and particuing vessel over a period of 2-4 minutes.After 7 minut larly enhanced whiteness achievedthrough-the practice ofof cleaning time have elapsed the cleaning system is thepresentinventiom.

charged to the still to separate water and distillable Individual shirtsof 65/35 polyester/cotton are cleaned organic contaminates from theperchloroethylene and the using the process of Example I modified asindicated begarments are centrifuged to a wet weight of about 60 low inthe sample identification with relative whiteness pounds. Following thecentrifugation step, 40 gallons determined on a Hunter Reflectometer.

Hunter rating 1 2 3 4 5 6 G(E) green reflectance excluding UV 79.9 75.673.5 78.9 81.6 80.5 B(I) blue reflectance including UV '91.7 82.9 81.989.8 93.1 90.8 B(E) bluereflectauce excluding UV 77.6 71.3 70.7 776.5,79.3 78.0 B(I)-B(E) ercent blue reflectance due to optical brightener)14.1 11.6 11.2 13.3 13.8 12.8

4B (I)3G(E (equation for relative whiteness) perchloroethylenecontaining 12 ounces of Emerbrite 3723 non-ionic detergent, alsoavailable from Emery Industries, Inc., is charged to the cleaning vesseland the garments are treated in a second cleaning cycle for anadditional seven minutes with the solvent being continuously filteredfor removal of insoluble soils from the system. With the completion ofthe second cleaning cycle, solvent is discharged and the garments arecentrifuged to a weight of about pounds. Residual solvent is evaporatedand the clothes are aerated and dried.

The white garments removed from the dry cleaning cylinder have beenthoroughly cleaned and are as and bright as comparable new garments.

The dry cleaning process of part (a)'of this example is repeated usingN-dodecyl-N-methyltaurine and naphthotriazolyl stilbene sulfonic acid asthe respective detergent and opticalbrightening materials with equallygood results.

White SAMPLE IDENTIFICATION (1) New control shirt I (2) 1 wearingthendry cleaned once in first cycle of Example I without brightener (3) 3wearingsdry cleaned after each wearing in only the second cycle 'ofExample I with no added brightener (4) 1 wearing-then dry'cleaned twice(5) '1' wearing-then' dry cleaned once (6) 1 wearing-then dry cleanedonce' Samples dry cleaned up to 25 times have not shown suflicientbrightener accumulation in the test fabrics to adversely affect otherdesired garment characteristics.

It is contemplated within the scope of the invention that othercompatible agents which affect the brightness of fabrics by operatingthrough other mechanisms and therefore not technically classifiable asoptical brighteners may be included in the dry cleaning formulation toenhance, modify or otherwise affect the appearance of the fabric. Forinstance, it has been found that dyes producing blue and violet tints onfabrics will enhance and at times synergize the effect produced by theoptical brightener formulation without added dye. This result isunexpected since it would seem logical that the tint would reduce lightreflection, thereby decreasing fabric brightness and causing the fabricto assume a grey appearance. As examples of other compositions which maybe employed at various points in the process to augment brightness,there may be mentioned certain film-forming resins and finishes such aspolyvinyl pyrrolidone.

As an example, a brightener formulation containing 15 p.p.m. TinoliteBrilliant Violet 41375 and 2 p.p.m. Tinolite Padding Brilliant Blue GL23, both available from Geigy Chemical Corporation, in addition to thewater-dispersible optical brightener produces a whiteness and brightnesswhen used in the dry cleaning process of Example I surpassing thatresulting from the use of the optical brightener without dye.

While various preferred embodiments of the present invention have beendescribed, it is to be understood that the scope of the invention is tobe limited solely by the appended claims in view of the specification.

What is claimed is:

1. A dry-cleaning composition consisting essentially of from about 0.01to about 1000 parts per million of a Water soluble, anionic, stilbeneoptical brightener which is a bis-triazinyl derivative of4,4'-diaminostilbene-2,2'- disulfonic acid prepared from one mole of thereaction product of two moles of cyanuric chloride and one mole of thedisodium salt of diaminostilbene disulfonic acid with two moles ofaniline; from about 0.04 to about 5 percent of a detergent selected fromthe group consisting of anionic, nonionic, and amphoteric detergents;from about 0.04 to about 7 percent of water; and a hydrophobic, organicdry-cleaning solvent.

2. The composition of claim 1, wherein the dry cleaning solvent isselected from the group consisting of halogenated hydrocarbon andpetroleum naphtha solvents.

3. The composition of claim 2, wherein said detergent is an amphotericdetergent.

4. The composition of claim 3, wherein said composition is comprised offrom about 0.1 to about 10 parts per million of said optical brightener,from about 0.3 to

about 2 percent of said detergent, and from about 0.5 to about 4 percentof water.

5. The composition of claim 4, wherein said dry cleaning solvent isselected from the group consisting of trichloroethylene,perchloroethylene, and Stoddards solvent.

6. The composition of claim 5, wherein said composition is comprised ofabout 2 parts per million of said optical brightener, about 0.375percent of said amphoteric detergent, and about 0.75 percent of water.

7. A process for dry-cleaning a textile structure comprising the step oftreating said textile structure with a dry cleaning compositionconsisting essentially of from about 0.01 to about 1000 parts permillion of a water soluble, anionic, stilbene optical brightener whichis a bis-triazinyl derivative of 4,4-diaminostilbene-2,2-disulfonic acidprepared from one mole of the reaction product of two moles of cyanuricchloride and one mole of the disodium salt of diaminostilbene disulfonicacid with two moles of aniline; from about 0.04 to about 5 percent of adetergent selected from the group consisting of anionic, nonionic, andamphoteric detergents; from about 0.04 to about 7 percent of water; anda hydrophobic, organic dry-cleaning solvent.

8. The process of claim 7, wherein said detergent is an amphotericdetergent.

9. The process of claim 8, wherein said composition is comprised of fromabout 0.1 to about 10 parts per million of said optical brightener, fromabout 0.3 to about 2 percent of said detergent, and from about 0.5 toabout 4 percent of water.

10. The process of claim 9, wherein said dry cleaning solvent isselected from the group consisting of trichloroethylene,perchloroethylene, and Stoddards solvent.

11. The process of claim 10, wherein said composition is comprised ofabout 2 parts per million of said optical brightener, about 0.375percent of said amphoteric detergent, and about 0.75 percent of water.

References Cited UNITED STATES PATENTS 1,948,045 2/1934 Parkhurst 2521712,643,198 6/1953 Savidge et al. 8142 2,717,824 9/1955 Avery 8-1423,177,207 4/1965 Siegel et al. 252899 3,335,091 8/1967 Gilbert 2521533,392,122 7/1968 Obayashi et al. 25289 3,394,173 7/1968 Hausermann 25289LEON D. ROSDOL, Primary Examiner W. E. SCHULZ, Assistant Examiner US.Cl. X.R.

